简介：Thefocusofthisstudyistoexaminebedstabilityandmorphologyinhigh-gradientgravel-bedstreams,andthustoimproveunderstandingofthevariousparametersgoverningthesedimentflowcharacteristicsinmountainstreams.Ultimately,thisknowledgecanbeusedtodesignpseudo-naturalchannels,asinthestreamsimulationmethodofculvertdesign;withthisinmind,prototypeconditionsareevaluatedinaflumewithslopesrangingfrom3%to7%,andparticlerelativesubmergencevaryingfrom0.5to2.5forthreebedsizedistributions.Theseexperimentsaredesignedtosatisfytheconditionsofdynamicsimilarityforflowandsediment,andtheyarepreferredoverfieldmeasurementssincetheyallowahighdegreeofcontrolovertestingconditions.Itisfoundthatsteppoolbedformsarethemostubiquitousfeaturesalongthegravelbed.Anewformulaisdevelopedthatcorrelatesstepheightwiththegravel-bedsizedistribution,relativesubmergenceoftheparticles,andtheFroudenumber.Thestepspacingisfoundtoberelatedtostepheightandstreambedlongitudinalslope.Flowresistanceisalsoexamined,andaformulaisdevelopedwhichaccountsfortheresistanceduetothebedforms(formresistance),aswellastheindividualsedimentparticles(grainresistance).